function isdefined( variable)
{
    return (typeof(window[variable]) == "undefined")?  false: true;
}


if (document.getElementsByTagName){
	document.getElementsByTagName('link')[0].disabled = true;
	document.getElementsByTagName('link')[1].disabled = true;
}

window.onload = function(e) {
  var cookie = readCookie("style");
  if ( isdefined(cookie) ) {
	var nr = cookie ? cookie : getPreferredStyleSheet();
	changeCSS(nr);
  }
}

window.onunload = function(e) {
  var nr = getActiveStyleSheet();
  createCookie("style", nr, 365);
}


function changeCSS(nr)
{
	if (document.getElementsByTagName)
		x = document.getElementsByTagName('link');
	else if (document.all)
		x = document.all.tags('link');
	else
	{
		alert('This script does not work in your browser');
		return;
	}
	nr--;
	for (var i=0;i<x.length;i++)
	{
		dis = !(i == nr);
		x[i].disabled = dis;
	}
}

function getActiveStyleSheet()
{
	if (document.getElementsByTagName)
		x = document.getElementsByTagName('link');
	else if (document.all)
		x = document.all.tags('link');
	else
		return 0;
	for (var i=0;i<x.length;i++)
	{
		if (x[i].disabled == false){
			return i+1;
		}
	}
	return 0;
}





function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}
function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}